The present invention relates to the writing of data to a tape drive and, more specifically, to a method for writing data to a tape in a tape drive used in a file system.
Tape drives can be used in file systems similar to hard disk drives (HDD). Tape drives compatible with LTO standards (LTO-5 or later) can be used in file systems. The tape used in LTO-compatible tape drives has a plurality of wraps (for example, 80). When data is written to such a tape and the writing of data to a single wrap has been completed, a so-called “wrap turn” operation is required to reverse the traveling direction of the tape and move to write data to the next wrap.
One type of file system is a Linear Tape File System (LTFS). Because data is written continuously to a tape drive in LTFS, a so-called delayed write function is required to write data to the tape while data accumulated in the buffer is successively transferred to the tape drive.
Because a LTFS tape drive with a delayed write function cannot write data to a tape during the seconds required to perform the wrap turn operation, the write data during this period simply accumulates in the buffer. Often, the buffer runs out of free space and the accumulation of data in the buffer is interrupted. Because an LTFS buffer is shared with other peripherals in addition to the host, there is a chance that data accumulation will be interrupted at each wrap turn. As a result, problems occur related to delays in writing data to LTFS tape drives.
Increasing the storage capacity of buffers has been considered as a way of preventing interruptions in the accumulation of data in buffers. However, regularly releasing a large amount of storage capacity for the LTFS is undesirable as the LTFS then monopolizes the resources of the host using the LTFS. Because LTFS is reconciled with other applications, its use of buffer capacity should be minimized in order to avoid data writing delays caused by wrap turns.